The present invention relates to steering equipment for work vehicles, and more particularly, to a control device for steering equipment for agricultural vehicles.
In agricultural vehicles, it is known to use a steering unit including a steering column having a longitudinal axis, a steering transmission shaft mounted inside the steering column for rotating about the longitudinal axis and a steering wheel mounted on the transmission shaft. Additionally, a control device for actuating a steering operating unit may be provided. The control device may be operable to induce conversion between a “conventional steering mode” and a “fast steering mode” as described in EP-A-1.142.773, now U.S. Published patent application No. 2001/0032461 A1.
The steering unit is designed to control the steering of a pair of wheels of the work vehicle, usually by means of a hydraulic steering valve. The steering valve enables the steering wheel to continue to rotate about the longitudinal axis even when the vehicle wheels have reached their maximum steering angle. Consequently, a given steering angle of the vehicle wheels does not necessarily correspond to a given position of the steering wheel about the longitudinal axis.
Therefore, the known steering equipment as described above presents the drawback that the control device is normally mounted on the dashboard of the vehicle. To actuate the control device, the vehicle operator, who is normally already occupied in operating other functions such as a gear change, must let go of the steering wheel with one hand to perform a relatively distracting operation. Moreover, the control device may require uninterrupted actuation in order to remain active. The vehicle operator may be forced to stop operating other functions and return both hands to the steering wheel for controlling steering.
Thus, the purpose of the present invention is to provide steering equipment for a work vehicle which is free from the drawbacks referred to above.